Merge commit '50d3e596bbe89c95615f96eb71f6bc5be737a1db' into Basilisk-releasev2018.07.18

# Conflicts:
#	browser/app/profile/firefox.js
#	browser/components/preferences/jar.mn

1 files changed, 6 insertions, 1 deletions

diff --git a/toolkit/components/thumbnails/BackgroundPageThumbs.jsm b/toolkit/components/thumbnails/BackgroundPageThumbs.jsm
index fded51cea..bd52e77e9 100644
--- a/toolkit/components/thumbnails/BackgroundPageThumbs.jsm
+++ b/toolkit/components/thumbnails/BackgroundPageThumbs.jsm
@@ -468,7 +468,12 @@ Capture.prototype = {
     };
 
     if (!data) {
-      done();
+      // If this background attempt failed, cause a dummy file to be saved, so
+      // that gets loaded instead of attempting again (and again).
+      // XXX: Perhaps we can create a placeholder image to use instead of "null"
+      // here, so it has something to show to the user?
+      PageThumbs._store(this.url, this.url, null, true)
+                .then(done, done);
       return;
     }